カーボンブラック含有加硫天然ゴムの亀裂先端に見出された多元的構造変化

抄録

Structure changes around the crack tip of natural rubber vulcanizates filled with carbon-black were investigated after a cycle of stretch-retraction. On the extension line of the crack, formation of a valley-like dent was newly found. The depth of the dent was about 10 μm. By the diffraction mapping using the micro X-ray beam, localization of crystals of paraffin, which has been mixed as plasticizer, along the valley-like dent was disclosed. These findings indicate the occurrence of large-scale mass transfer which leads to three-dimensional transformation and segregation of the low molecular weight material along with the strain-induced crystallization around the crack tip.